IDNetters Forums

Technical News & Discussion => Networking & Routers => 2-Wire 2700 => Topic started by: Simon on Feb 06, 2008, 21:59:40

Title: Resets page
Post by: Simon on Feb 06, 2008, 21:59:40
Poking about in the 2700 settings, I found this page:

http://gateway.2wire.net/xslt?PAGE=J21&THISPAGE=J05&NEXTPAGE=J21

I was wondering what Reset DSL Connection actually does?  It says, "Retrains your DSL connection on the same line."  Would it really force a retrain, and possibly a subsequently faster connection?  Needless to say, I haven't clicked it!  ;D
Title: Re: Resets page
Post by: kinmel on Feb 06, 2008, 22:17:47
Yep, it does what it says on the box.

Disconnects from BT and re-syncs; best done of a morning when your SNR is at it's best.
Title: Re: Resets page
Post by: Sebby on Feb 06, 2008, 22:28:15
Indeed, it'll force a re-sync without having to reboot the router.

Remember not to do too many in a row, though, as it can mess up your target SNRM. Actually, don't you have a 15dB target SNRM, Simon? IIRC, you do, and you should ideally be trying to stay sync'd for 14 days. ;)
Title: Re: Resets page
Post by: Simon on Feb 06, 2008, 22:42:37
OK, I'll leave it be then.

Am I getting confused though?  Is this the same as the line retraining that happens when you switch from fixed rate broadband to Max, and takes up to 10 days?
Title: Re: Resets page
Post by: Sebby on Feb 06, 2008, 22:51:09
Nope, this is different.

When you first move to Max, your target SNRM is 6dB (the lowest and default figure). If your router loses sync several times in an hour (10, I believe), the exchange sees this as instability and pushes the target SNRM up by 3dD, causing your router to sync lower, hence (hopefully) providing more stability. This can continue to a maximum figure of 15dB (this is where you are now). In practice, I've found the exchange to be a bit "heavy-handed" and push it straight up from 6 to 15dB, so this might be what happened to you.

You're at 15dB as you had a modem before, and the exchange has probably seen all the times the modem has connected/disconnected as instability.

The way to get the target SNRM to reduce is by leaving the router sync'd for 14 days (but maybe leave it 15 to be on the safe side). The exchange then sees the connection as stable and will reduce the target SNRM to 12dB. Another 14/15 days and you should get to 9dB, then finally 6dB after another period with no re-syncs. This is nothing to do with the training period; it's just the way to "prove" to the exchange that things are stable and to let you have another try at a lower target SNRM.

I hope this makes sense! :)
Title: Re: Resets page
Post by: Simon on Feb 06, 2008, 23:07:41
It does, but I haven't had a modem for over a year.  I had a DG834G before I switched to the 2700, and unless it kept losing sync without my noticing, surely I should have been on the lower SNRM anyway? 
Title: Re: Resets page
Post by: Lance on Feb 06, 2008, 23:27:32
Sometimes the 14 day thing doesn't work. I suggest leaving the 2wire for the 14 days, checking the logs for any resyncs and if on the 15th day you resync and still have the 15db margin, speak to support.  :)
Title: Re: Resets page
Post by: Sebby on Feb 06, 2008, 23:28:59
As Lance says, for some it doesn't work. There doesn't appear to be a reason why! I'd ask IDNet to ask BT to do it manually, the reason for which being that the DLM isn't doing its job of automatically reducing the target SNRM. :)
Title: Re: Resets page
Post by: Simon on Feb 07, 2008, 00:14:24
OK, I'll hold on and see what happens.  :)
Title: Re: Resets page
Post by: Rik on Feb 07, 2008, 09:25:00
It might also be worth running Routerstats, Simon, to get a picture of your noise margin.
Title: Re: Resets page
Post by: Simon on Feb 07, 2008, 11:52:33
I'll check that out, Rik.
Title: Re: Resets page
Post by: Rik on Feb 07, 2008, 11:54:50
It's often quite revealing, for example, I know that the street light outside costs me 1db of margin having observed it in action.